Abstract

Aegilops tauschii, the diploid progenitor of the wheat D genome, is a readily accessible germplasm pool for wheat breeding as genes can be transferred to elite wheat cultivars through direct hybridization followed by backcrossing. Gene transfer and genetic mapping can be integrated by developing mapping populations during backcrossing. Using direct crossing, two genes for resistance to the African stem rust fungus race TTKSK (Ug99), were transferred from the Ae. tauschii accessions TA10187 and TA10171 to an elite hard winter wheat line, KS05HW14. BC2 mapping populations were created concurrently with developing advanced backcross lines carrying rust resistance. Bulked segregant analysis on the BC2 populations identified marker loci on 6DS and 7DS linked to stem rust resistance genes transferred from TA10187 and TA10171, respectively. Linkage maps were developed for both genes and closely linked markers reported in this study will be useful for selection and pyramiding with other Ug99-effective stem rust resistance genes. The Ae. tauschii-derived resistance genes were temporarily designated SrTA10187 and SrTA10171 and will serve as valuable resources for stem rust resistance breeding.

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Acknowledgments

This is contribution number 13-105-J from the Kansas Agricultural Experiment Station. This work was funded by the Durable Rust Resistance in Wheat project, Cornell University through a grant from The Bill & Melinda Gates Foundation and the USDA-ARS (Appropriation #5430-21000-006-00D). We thank Amy Bernardo, Paul St. Amand, Katherine Kaus, and Mitchell Keller for technical assistance. Dr. Robert A. McIntosh gave suggestions that improved this manuscript.